Method and apparatus for operating in wells



Feb. N, 1969 H. s. ARx-:NDT 3,426,851

METHOD AND APPARATUS FOR OPERATING IN WELLS Filed neo. 15, 195s Fire 2O Z7 Detector Deection 30 INVENTORL 'f Hurry S. Arendt,

ATTORNEY.

United States Patent O 3,426,851 METHOD AND APPARATUS FOR OPERATING IN WELLS Harry S. Arendt, Bellaire, Tex., assigner, by mesne assignments, to Esso Production Research Company,

Houston, Tex., a corporation of Delaware Filed Dec. 15, 1958, Ser. No. 730,524

U.S. Cl. 166-255 12 Claims Int. Cl. E21b 43/11, 47/00, 43/119 This invention generally concerns multiple zone well operations. More particularly, the invention concerns loeating pipe strings arranged in a borehole relative to the position of a well tool. In its more particular aspects, the invention concerns locating pipe strings arranged in a borehole relative to the direction of fire of a gun per forator and orienting the gun perforator to direct the re thereof in a direction away from one or more of the pipe strings to avoid perforation thereof or toward one or more of the pipe strings to cause perforation thereof.

In multiple zone well operations, a plurality of pipe strings are arranged in a borehole which penetrates a plurality of vertically spaced productive zones and production fluids from each zone are conducted independently to the earths surface through these pipe strings. In order to perforate a particular interval, a gun perforator is run in the borehole and fired in a direction to cause penetration of the productive formation. However, when at least two pipe strings are positioned adjacent the interval to be perforated, it is necessary to direct the tire of the gun perforator to avoid striking and perforating one or more of the pipe strings other than the pipe string through which the gun perforator is run. Also, Vin well operations wherein the borehole contains a plurality of pipe strings, it may be desired to direct the tire of the gun perforator to perforate one or more of the pipe strings, as, for example, when it is necessary to establish subsurface communication between pipe strings during blowouts, workovers, etc.

These desired results are achieved by the present invention which provides method and apparatus for locating additional pipe strings in a borehole relative to the direction of re of a gun perforator; for orienting the gun perforator to direct the fire thereof in any desired radial direction; and for tiring the gun perforator to avoid perforating a particular pipe or pipes or for perforating a particular pipe or pipes, as may be desired. Radioactivity detection techniques are utilized to locate the pipe and particularly the technique of detecting induced secondary radiation resulting from bombardment by primary radiation.

The invention is advantageous in many ways. For example, it avoids the use of gun guides; it permits running pipe strings in the well separately; it permits full and constant openings through all of the pipe strings; and it avoids the possibility of an incorrect orientation should a pipe string rotate or slip in a clamp clamping pipe strings together or should the original alignment of the pipe strings be in error.

These purposes and other purposes of the invention will be apparent from a description thereof taken in conjunction with the drawings wherein:

FIG. 1 is a cross-sectional view of the earths subsurface showing a borehole having arranged therein two pipe strings, one of which contains a tool for locating pipe and for gun perforating; also shown is a schematic illustration of the surface equipment utilized for registering detection of pipe and for iiring the gun perforator;

FIG. 2 is a view taken on lines 2 2 of FIG. 1 illustrating the direction of tire of the gun perforator relative to the location of the detected pipe; and

ICC

FIG. 3 is a vertical, partly sectional view of the positioning portion of the tool of FIG. 1.

Referring to the drawings in greater detail, in FIG. 1 is shown a borehole 10 penetrating a sub-surface productive formation 11. Two eccentric, spaced-apart pipe strings 12 and 13 are arranged in borehole 10 and cemented therein by means of cement 14. A pipe detector and perforator tool, generally designated 15, is suspended in pipe string 12 by means of a multi-electrical conductor cable 16. Tool 15 includes a pipe locator section 17 which comprises a source of bombarding radiation 18, a radiation shield 19, and a radiation detector 20 provided with a radiation collimating shield 21; a gun section 22 which comprises a plurality of gun elements 23 which may be suitably of the jet type or the bullet type; and a tool positioner section 24 which will be described later herein with regard to FIG. 3. A plurality of vertically spaced-apart restrainers and centralizers 25 are arranged on tool 15. These members may comprise a number of circumferentially arranged radially extending wire elements adapted to enga-ge the interior surface of pipe string 12. Members 25 not only serve to maintain tool 15 in a central position relative to the wall of pipe string 12 but also function to restrain random rotational movement of the tool. A swivel 26 may be employed to interconnect cable 16 and tool 15 in order to avoid excessive winding of cable 16 when tool 15 is raised and lowered in the borehole.

FIG. 2 illustrates positioning of tool 15 in pipe string 12 so that the directions of fire 27 of gun elements 23 are away from the direction of pipe detection 28. Pipe detection direction 28 is facing toward pipe string 13.

Tool positioner 24 is shown in detail in FIG. 3 and includes a housing 30 provided with fluid inlet and outlet ports 31 and 32, respectively; a shaft 33 which has a1'- ranged thereon helically configured vanes or Iblades 34 poistioned within housing 30; and a flap valve 35 adapted to allow downward flow of fluid through ports 31, housing 30, and outlet ports 32 and to prevent upward flow of iluid into housing 30l through ports 32.

Cable 16 extends to the surface of the earth where it connects to a gun perforator switch 36 adapted to tire the gun perforator and a radiation detector indicator 37 adapted to provide indications of the detected radiation. This surface equipment includes, also, power means for supplying power for ring the gun perforator, for transmitting detected radiation information and, if necessary, for providing power for the radiation source When it is desired to perforate an interval of formation 11, tool 15 is lowered on cable 16 through pipe string 12 until it is positioned adjacent the portion of formation 11 it is desired to perforate. Tool 15 is maintained stationary by means of restrainers 25 and formation 11 is bombarded by means of the source of radiation 18 and the radiation induced by the bombardment is detected by means of shielded detector 20. The detected radiation is indicated at the detector indicator 37. Shield 21 collimates the detected radiation to conne the radiation detected to a limited arc, as, for example, an arc of 45 of the well bore. Tool 15 is then raised in the borehole by means of cable 16. During raising of tool 15, fluid 38 in pipe string 12 enters housing 30 through inlet ports 31 and discharges from housing 30 through flap valve 3S and outlet ports 32. During passage of this fluid through the housing, vanes 34 are caused to rotate which, in turn, rotates housing 30 to which vanes 34 are connected. Rotation of housing 30 rotates also the gun and pipe locator sections 22 and 17, respectively, connected thereto. Swivel 26 prevents excessive winding of cable 16 when tool 15 is rotated. Tool 15 is lowered then to its original position and detected radiation readings are again made. During lowering, tool 15 does not rotate because flap valve 35 prevents iiow of fluid through housing 30. These steps of raising and lowering tool and taking detected radiation indications at the same level each time are repeated until the position of pipe string 13 relative to the direction of the collimated detected radiation is established. The tool may be successively rotated to obtain comparative readings through a full 360 circle. Detection may be based on a maximum or a minimum reading as desired. Also, as desired, the bombardment detection and indications of detected radiation may be made continuously while tool 15 is rotated, although the procedure wherein indications are made while tool 15 is stationary is preferred.

In FIG. 2, the direction of the collimated detected induced radiation 28 is in the direction of pipe string 13 and the direction of lire 27 is away from the direction of pipe string 13. Therefore, when detector transmits information to the indicator 37 indicating that the direction of detection 28 is directed toward pipe string 13, gun perforator 22 is fired by means of the surface control 36.

Restrainers 25 aid in maintaining tool 15 stationary once the tiring position has been established and they also function to maintain tool 15 centralized so that the readings of detected radiation will be consistent. If desired, instead of having tool 15 centralized in pipe string 12, biasing means may be employed to bias the tool against the wall of pipe string 12. Also, if desired, other restraining means such as bow springs may be employed in conjunction with or in place of members 25.

Source of radiation 18 may be fast neutrons or gamma rays. Thus, the source may be an alpha-neutron (am), deuteron-neutron (d,n), or proton-neutron (p,n) reaction wherein the alpha particle, deuteron, or proton is accelerated by an electric field and thereby caused to interact with selected target materials in order to produce neutrons of various energies within the contines of source 18; or the radiation source may be neutrons originating from a radium-beryllium, or polonium-beryllium source. Sources of high energy gamma radiation which may be employed are radioactive Na24, La140, Sb124, C060, or high energy gamma rays produced by various reactions in high energy particle machines in a manner well known to the art in nuclear physics. For example, the bombardment of lithium by protons produces high energy 17 mev. gammas.

Detector 20 detects slow neutrons or gamma rays or fast neutrons and for detection of this radiation ionization chambers, Geiger-Mueller tubes, and scintillation counters may be used.

Shields 19 and 21 are formed of radiation absorbing or moderating materials such as lead, tungsten, paraflin, boron, cadmium, etc., which materials are capable of absorbing or moderating the induced radiation.

If the source of radiation is neutrons and the induced radiation is neutrons, then as tool 15 is placed in position by raising and lowering thereof, a lower reading on indicator 37 is observed when the horizontal arc of investigation of detector 20 is toward steel pipe string 13 than when the arc of investigation of detector 20 is away from pipe string 13.

However, instead of detecting pipe string 13 itselfit may be desirable to detect the peak energy from a specic chemical element in accordance with spectral gamma ray logging practice. For example, a compound containing sulfur when bombarded with neutrons emits a gamma ray of 4.3 mev. energy. By making detector 20 sensitive to this energy according to known nuclear physics practice, the location of the pipe string or pipe strings containing this element is readily determined. Other elements, such as chlorine, may be employed in the same manner. The chemical element to be detected may be spotted or positioned adjacent formation 11, in any desired manner, as, for example, by mixing the chemical element with a tiuid contained in pipe string 13; by coating a composition containing the chemical element on the interior or exterior of pipe string 13; or by placing the chemical element in a container and lowering the container on a wire line in pipe string 13 to adjacent formation 11, etc. Lowering of a container containing the chemical element on a wire line is the least desirable of the procedures because it requires added surface facilities for running the additional wire line.

The invention is applicable to so-called tubingless completions; that is, wells completed without setting casing. This procedure, which is illustrated in FIG. l, includes running the desired pipe strings in the borehole and cementing the pipe strings in place. The invention is also applicable to cased wells; that is, where a casing is run in the borehole and cemented in place and the pipe strings are arranged within the casing.

Positioner 24 is hydraulically operated by means of duid contained in pipe string 12 as has been dscribed and this is the preferred form of apparatus for positioning tool 15. However, other types of apparatus are within the scope of the invention. For example, a mechanically operated type positioning device, such as disclosed and claimed in U.S. patent application Ser. No. 780,387, entitled, Well Operation Method and Apparatus, filed Dec. l5, 1958, by J. C. McDuliie, Ir., may be employed instead.

Only two pipe strings have been shown and described in the description of the operation of the invention. However, the invention encompasses method and apparatus for orienting tool 15 wherein more than two pipe strings are located in the well bore. When more than two pipe strings are located in the well bore, the procedure is the same as that described when only two pipe strings are in the well bore except it is preferable to direct the fire of the gun perforator in only one direction in order to insure that the direction of lire is away from the pipe strings. In this instance, also, instead of having the direction of detection opposite to or in another direction other than the direction of re, it is preferred to have the direction of detection coincide `with the direction of re. Thus, in a 360 revolution, there will be at least one direction in which the detector indicates no pipe string. Since this is also the direction of lire, the pipe strings in the well bore will be avoided when the gun perforator is fired.

In the circumstances wherein it is desired to intentionally perforate a pipe string or pipe strings, the direction of lire of the gun perforator is positioned relative to the direction of detection in a manner similar to the procedure described for avoiding perforating the pipe strings except the line of re of the gun perforator will be in position to perforate the pipe string or pipe strings.

Although shielding of the detector only was described herein, it is to be understood that the scope of the invention includes shielding of the radiation source instead of or in conjunction with shielding of the radiation detector. The same principles of confining the area of investigation to a limited arc apply.

Having fully described the method, apparatus, objects, and operation of my invention, I claim:

1. A method for perforating in a well bore having a plurality of pipe strings arranged therein in side-by-side relationship comprising the steps of:

arranging in one pipe string a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe llocator means having a selected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation, and a detector of said induced radiation;

rotating said tool and detecting by means of said pipe locator means the radial position 0f said other pipe string relative to said selected angular position of said tool;

further rotating said tool to orient said perforator relative to said other pipe string; and actuating said perforator. 2. A method for perforating in a Well bore having at least one pipe string arranged therein comprising the steps of:

arranging in said well bore a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe locator means having a selected radial direction of pipe detection fixed relative to said `direction of perforation and capable of locating the radial position of said pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation and a detector of said induced radiation; rotating said tool and detecting by means of said pipe llocator means the radial position of said pipe string relative to said selected angular position of said tool;

further rotating said tool to orient said perforator relative to said pipe string; and

actuating said perforator.

3. A method for perforating in a well bore having a plurality of pipe strings arranged therein in side-by-side relationship comprising the steps of:

arranging in one pipe string a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe locator means having a selected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact With materials in their path to provide induced radiation, and a detector of said induced radiation;

rotating said tool to detect by means of said pipe locator means the radial position of said other pipe string relative to said selected angular position of said tool andto orient said perforator relative to said other pipe string; and

actuating said perforator.

4. A method for perforating in a Well bore having at least one pipe string arranged therein comprising the steps of:

arranging in said Well bore a rotatable tool provided with a perforator having a selected radial direction of perforation and With pipe locator means having a a selected radial direction of pipe detection iixed relative to said direction of perforation and capable of locating the radial position of said pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation, and a detector of said induced radiation;

rotating said tool to detect by means of said pipe locator means the radial position of said pipe string relative to said selected angular position of said tool and to orient said perforator relative to said pipe string; and

actuating said perforator.

5. A method for perforating in a Well bore having a plurality of pipe strings arranged therein in side-by-side relationship comprising the steps of:

arranging in one pipe string a rotatable tool provided with a perforator having a selected radial direction of perforation and With pipe locator means having a selected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool;

rotating said tool to detect by means of said pipe 1ocator means the radial position of said other pipe string relative to said selected angular position of said tool and to orient said perforator relative to said other pipe string; and

actuating said perforator.

6. A method for perforating in a Well bore having a plurality of pipe strings arranged therein in side-byside relationship comprising the steps of:

arranging in one pipe string a rotatable tool provided with a perforator having a selected radial direction of perforation and With pipe locator means having a Vselected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation, and a `detector of said induced radiation having a selected radial direction of induced radiation detection;

rotating said tool to detect by means of said pipe locator means the radial position of said other pipe string relative to said selected angular position of said tool and to orient said perforator relative to said other pipe string; and

actuating said perforator.

7. A method for perforating in a well bore having a plurality of pipe strings arranged therein in side-by-side relationship comprising the steps of:

arranging in one pipe string a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe locator means having a selected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation having a selected radial direction of radiation emission, the rays of which coact with materials in their path to provide induced radiation, and a detector 'of said induced radiation having a selected radial direction of induced radiation detection;

rotating said tool to detect by means of said pipe locator means the radial position of said other pipe string relative to said selected angular position of said tool and to orient said perforator relative to said other pipe string; and

actuating said perforator.

8. In a borehole extending from the earths surface through subsurface formations, said borehole containing first and second pipe strings both of which extend downwardly from the earths surface in side-by-side relationship, a method of perforating in a manner so as to avoid perforation of said second pipe string which comprises the steps of:

lowering in said first pipe string to adjacent one of said formations a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe locator means having a selected radial direction of pipe detection lixed relative to said direction of perforation and capable of locating the radial position of said second pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation, and a detector of said induced radiation;

rotating lsaid tool to detect by means of said pipe locator means the radial position of said second pipe string relative to said selected angular position of said tool and to orient said perforator to direct the direction of perforation thereof away from said second pipe string; and

actuating said perforator.

9. In a borehole extending from the earths surface through subsurface formations, said borehole containing iirst, second, and third pipe strings all of which extend downwardly from the earths surface in side-by-side relationship a method of perforating in a manner so as to avoid perforation of said second and third pipe strings which comprises the steps of:

lowering in said iirst pipe string to adjacent one of said formations a rotatable tool provided with a perforator having a selected radial direction of perforation and with pipe locator means having a selected radial direction of pipe detection fixed relative to said direction of perforation and capable of locating the radial positions of said second and third pipe strings relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path to provide induced radiation, and a detector of said induced radiation;

rotating said tool to detect by means of said pipe lowith a perforator having a selected radial direction of perforation and with pipe locator `means having a selected radial direction of pipe detection ixed relative to said direction of perforation and capable of locating the radial position of another pipe string relative to a selected angular position of said tool, said pipe locator means including a source of radiation, the rays of which coact with materials in their path including selected material provided in said other pipe string to provide induced radiation;

rotating said tool to detect by means of said pipe locator means the radial position of said other pipe string relative to said selected angular position of said tool and to orient said perforator relative to said other pipe string; and

actuating said perforator.

11. A method for perforating in a well bore having a plurality of pipe stringsarranged therein in side-by-side relationship comprising the steps of arranging in one of said pipe strings a rotatable tool provided with a perforator having a selected radial -direction of perforation and with pipe locator means `having a selected radial direction of pipe detection iixed relative to said direction of perforation and capable of locating the radial position of at least one other of said pipe strings relative to a selected angular position of said tool;

orienting said tool to a desired radial direction of perforation as determined by said locator means; and

actuating said perforator.

12. Apparatus for perforating in a well bore penetrating a subsurface formation and having a plurality of juxtaposed pipe strings arranged therein comprising:

a rotatable tool adapted to be arranged in one of said pipe strings and comprising a body provided with a perforator thereon Ihaving a selected angular direction of perforation relative to the axis of said body; pipe locator means including a source of radiation and a detector of the radiation produced by said source of radiation mounted on said body whereby the radial position of another of said pipe strings relative to a selected rotational position of said body can be detected; means capabale of causing rotation of said tool; said perforator and said pipe locator means being angularly iixed relative to each other; and means for actuating said perforator.

References Cited UNITED STATES PATENTS 2,228,634 1/1941 Ennis 166-4 2,322,634 6/1943 Howell et al. 2SC- 83.6 2,436,503 2/1948 Cleveland l66-55.5 2,476,137 7/1949 Doll 166-4 2,653,007 9/1953 Aston 166-55 2,785,754 3/1957 True 166-55.1 2,544,979 3/1951 Brokaw et al. Z55-1.65 2,476,136 7/1949 Doll 166-4 45 DAVID H. BROWN, Primary Examiner.

U.S. Cl. X.R. 

11. A METHOD FOR PERFORATING IN A WELL BORE HAVING A PLURALITY OF PIPE STRINGS ARRANGED THEREIN IN SIDE-BY-SIDE RELATIONSHIP COMPRISING THE STEPS OF: ARRANGING IN ONE OF SAID PIPE STRINGS A ROTATABLE TOOL PROVIDED WITH A PERFORATOR HAVING A SELECTED RADIAL DIRECTION OF PERFORATION AND WITH PIPE LOCATOR MEANS HAVING A SELECTED RADIAL DIRECTION OF PIPE DETECTION FIXED RELATIVE TO SAID DIRECTION OF PERFORATION AND CAPABLE OF LOCATING THE RADIAL POSITION OF AT LEAST ONE OTHER OF SAID PIPE STRINGS RELATIVE TO A SELECTED ANGULAR POSITION OF SAID TOOL; ORIENTING SAID TOOL TO A DESIRED RADIAL DIRECTION OF PERFORATION AS DETERMINED BY SAID LOCATOR MEANS; AND ACTUATING SAID PERFORATOR. 